Skip to main content
U.S. flag

An official website of the United States government

Aaron DeLonay

Aaron is an Ecologist at the Columbia Environmental Research Center.

Science and Products

link
image of eco-flume pump system

CERC Eco-flume

The CERC Eco-flume is a continuous-loop, racetrack style flume. It is housed in a 1,350 square-foot laboratory at CERC and will be used to study transport phenomena and biophysical processes in river environments.
By
Columbia Environmental Research Center
link

CERC Eco-flume

The CERC Eco-flume is a continuous-loop, racetrack style flume. It is housed in a 1,350 square-foot laboratory at CERC and will be used to study transport phenomena and biophysical processes in river environments.
Learn More
link
Female pallid sturgeon, PLS11-007, is released back into the Missouri River after an ultrasound evaluation

Comprehensive Sturgeon Research Project Blog - 2018

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon. 

link

Comprehensive Sturgeon Research Project Blog - 2018

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon. 

Learn More
link

Comprehensive Sturgeon Research Project Blog - 2021

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon.
By
Columbia Environmental Research Center
link

Comprehensive Sturgeon Research Project Blog - 2021

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon.
Learn More
link

Comprehensive Sturgeon Research Project Blog - 2020

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon.
By
Columbia Environmental Research Center
link

Comprehensive Sturgeon Research Project Blog - 2020

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon.
Learn More
link
USGS

Comprehensive Sturgeon Research Project Blog - 2019

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon.
By
Columbia Environmental Research Center
link

Comprehensive Sturgeon Research Project Blog - 2019

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon.
Learn More
link
USGS

Pallid Sturgeon Early Life

CERC biologists focus on improving understanding of biomechanics of eggs, free embryos, and larvae through direct observation and measurement. An improved understanding of biomechanics – how biotic conditions and processes interact with physical processes to result in changes in survival – is necessary to create quantitative links between management actions and population-level results.
By
Columbia Environmental Research Center
link

Pallid Sturgeon Early Life

CERC biologists focus on improving understanding of biomechanics of eggs, free embryos, and larvae through direct observation and measurement. An improved understanding of biomechanics – how biotic conditions and processes interact with physical processes to result in changes in survival – is necessary to create quantitative links between management actions and population-level results.
Learn More
link
USGS

Adult Pallid Sturgeon Reproductive Ecology

CERC fish biologists study migrations, reproductive cues, and spawning behaviors of reproductive wild and hatchery-origin pallid sturgeon (HOPS) in the Missouri River Basin.
By
Species Management Research Program, Columbia Environmental Research Center
link

Adult Pallid Sturgeon Reproductive Ecology

CERC fish biologists study migrations, reproductive cues, and spawning behaviors of reproductive wild and hatchery-origin pallid sturgeon (HOPS) in the Missouri River Basin.
Learn More
link
USGS

Comprehensive Sturgeon Research Project Blog - 2016

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon. 

 

link

Comprehensive Sturgeon Research Project Blog - 2016

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon. 

 

Learn More
link
Female pallid sturgeon, PLS11-007, is released back into the Missouri River after an ultrasound evaluation

Comprehensive Sturgeon Research Project (CSRP)

The Comprehensive Sturgeon Research Project (CSRP) is a multidisciplinary project conducted in cooperation with the U.S. Army Corps of Engineers, Missouri River Recovery Program–Integrated Science Program. CERC scientists are working with river scientists and man­agers to develop methods, baseline information, and research approaches that are critical contributions to recovery success of the...
By
Ecosystems Mission Area, Species Management Research Program, Columbia Environmental Research Center
link

Comprehensive Sturgeon Research Project (CSRP)

The Comprehensive Sturgeon Research Project (CSRP) is a multidisciplinary project conducted in cooperation with the U.S. Army Corps of Engineers, Missouri River Recovery Program–Integrated Science Program. CERC scientists are working with river scientists and man­agers to develop methods, baseline information, and research approaches that are critical contributions to recovery success of the...
Learn More
link
Female pallid sturgeon, PLS11-007, is released back into the Missouri River after an ultrasound evaluation

Comprehensive Sturgeon Research Project Blog - 2017

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon. 

link

Comprehensive Sturgeon Research Project Blog - 2017

The USGS Comprehensive Sturgeon Research Project is a multi-year, interdisciplinary research study to determine factors leading to spawning and survival of the endangered pallid sturgeon and the closely related shovelnose sturgeon. 

Learn More

Observations of survival and hatch of developing pallid sturgeon embryos in relation to experimental substrate and sediment cover

This dataset documents the number of normally developed hatched free embryos, abnormally developed hatched free embryos, and viable unhatched embryos from two laboratory trials (shovelnose sturgeon during April and pallid sturgeon during May 2016) in substrate conditions designed to simulate potential fates within a dynamic riverine environment. Trials were performed with substrate treatments that
By
Columbia Environmental Research Center

Developmental stage and length of Pallid Sturgeon and Shovelnose Sturgeon free embryos reared at a constant temperature

This dataset documents the length and developmental stage of pallid sturgeon and shovelnose sturgeon free embryos from the time of hatch through melanin plug expulsion (the approximate onset of exogenous feeding) reared in the laboratory at a constant temperature. Free embryos from 4 pallid sturgeon crosses and 7 shovelnose sturgeon crosses were reared separately in the laboratory at a mean temper
By
Columbia Environmental Research Center

Cumulative thermal units and developmental stage of Pallid Sturgeon free embryos reared at multiple temperatures

This dataset documents the onset of developmental stages of pallid sturgeon free embryos from hatch through melanin plug expulsion, when reared in the laboratory at five nominal temperatures (14, 17, 20, 23, and 26 degrees Celsius, degrees C). Onset of developmental stages were recorded in days post-hatch (DPH) and cumulative thermal units (CTU). CTU are calculated as the sum of water temperature,
By
Columbia Environmental Research Center

Ploidy and genome size estimates of artificially produced larval pallid sturgeon, Scaphirhynchus albus

Data consist of flow cytometry files (.FCS) that were generated in the analysis of larval pallid sturgeon specimens. Nuclei from produced larval sturgeon somatic cells were analyzed using flow cytometry to estimate genome size and assign ploidy. Freshly collected rainbow trout (Oncorhynchus mykiss), largemouth bass (Micropterus salmoides), or pallid sturgeon blood were used as external controls, w
By
Columbia Environmental Research Center

Microsatellite genotypes and DNA yield of artificially produced larval pallid sturgeon, Scaphirhynchus albus

Data consist of genotypes for pallid sturgeon and paddlefish broodstock and artificially-produced larvae at 19 sturgeon microsatellite loci and four paddlefish loci. Microsatellite genotypes allowed confirmation of homozygous sturgeon DNA and absence of paddlefish DNA in haploid gynogens. Data also consist of DNA yield estimates for haploid gynogens for proof of concept that haploid gynogens can p
By
Columbia Environmental Research Center

Pallid Sturgeon Spawning Habitat in the Lower Missouri River

Lack of reproduction has been hypothesized to be a factor in the decline of the pallid sturgeon (Scaphirhynchus albus) through much of its range. Spawning habitat and behavior have only recently been documented on the Lower Missouri River, which comprises over 1,300 river kilometers of undammed river. This data consists of habitat measurements for ten pallid sturgeon spawning events from 2008-2013
By
Columbia Environmental Research Center
Filter Total Items: 42
Image: Seining for Sturgeon
link
Image: Pallid Sturgeon Egg Adhesion
link
Image: Surgical Implantation of an Acoustic Telemetry Transmitter
link
Image: Acoustic Telemetry Transmitter
link
Image: Counting Free Embryo Lake Sturgeon
link
Image: Lake Sturgeon at CERC
link
Image: Adult Female Pallid Sturgeon
link
Image: Sorting Samples
link
Image: Radio Telemetry Tracking
link
Image: Sidescan Sonar of the Yellowstone River
link
Image: Substrate Arrangement Of A CERC Pond
link
Image: Free Embryo
link
Image: Eggs and Milt Being Mixed
link
Image: Milt Collection
link
Image: Experimental Stream Section
link
Image: Free Embryo Sampling in the Platte and Missouri Rivers
link
Image: Pallid Sturgeon in Dip Net
link
Image: Pallid Sturgeon Holding Tanks
link
Image: Hartsburg, MO
link
Image: Hermann, MO
link
Image: Male Reproductive Pallid Sturgeon
link
Filter Total Items: 49

The effects of substrate and sediment burial on survival of developing pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (S. platorynchus) embryos

The shovelnose sturgeon (Scaphirhynchus platorynchus) and endangered pallid sturgeon (S. albus) deposit demersal and adhesive eggs in swift currents, near or over coarse substrate. Hydrographic surveys have demonstrated the dynamic nature of spawning habitats and that coarse substrates may episodically be buried (partially or completely) by fine sediments. To evaluate embryo survival of both speci
Authors
Kimberly Chojnacki, Amy E. George, Aaron J. Delonay
By
Ecosystems Mission Area, Columbia Environmental Research Center

Haploid gynogens facilitate disomic marker development in paleotetraploid sturgeons

Acipenseriformes (sturgeons and paddlefishes) are of substantial conservation concern, and development of genomic resources for these species is difficult due to past whole genome duplication. Development of disomic markers for polyploid organisms can be challenging due to difficulty in resolving alleles at a single locus from those among duplicated loci. In this study, we detail the development o
Authors
Richard Jr Flamio, Dominic G Swift, David S Portnoy, Kimberly Chojnacki, Aaron J. Delonay, Jeffrey Powell, Patrick Braaten, Edward J. Heist
By
Ecosystems Mission Area, Columbia Environmental Research Center

Ontogenetic development of pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (Scaphirhynchus platorynchus) from hatch through yolk absorption

Sturgeons have a complex free-embryo period extending from hatch to the initiation of exogenous feeding. Although available for some sturgeon species of the genus Acipenser, descriptions of the developmental stages of free embryos of the genus Scaphirhynchus are lacking. We characterised the ontogenetic development of pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (S. platorynchus)
Authors
Kimberly Chojnacki, Marlene J Dodson, Amy E. George, James Candrl, Aaron J. Delonay
By
Ecosystems Mission Area, Columbia Environmental Research Center

Production of haploid gynogens to inform genomic resource development in the paleotetraploid pallid sturgeon (Scaphirhynchus albus)

Order Acipenseriformes (sturgeons and paddlefishes) is an ancient lineage of osteichthyan fishes (>200 million years old) with most extant species at conservation risk. A relatively basal species, the pallid sturgeon, Scaphirhynchus albus, is a federally endangered species native to the Mississippi and Missouri River basins. Hybridization with sympatric shovelnose sturgeon, S. platorynchus, is one
Authors
Richard Flamio Jr., Kimberly Chojnacki, Aaron J. Delonay, Marlene J Dodson, Rachel M. Gocker, Jill Jenkins, Jeffrey Powell, Edward J. Heist
By
Ecosystems Mission Area, Columbia Environmental Research Center, Wetland and Aquatic Research Center

Physical characteristics and simulated transport of pallid sturgeon and shovelnose sturgeon eggs

The imperiled pallid sturgeon (Scaphirhynchus albus) and closely related, but more common, shovelnose sturgeon (S. platorynchus) are believed to broadcast adhesive, demersal eggs in the current and over coarse substrate in turbid rivers of the North American midcontinent. It has been hypothesized that eggs settle immediately following fertilization, but field conditions preclude direct observation.
Authors
Kimberly Chojnacki, Susannah O. Erwin, Amy E. George, James Candrl, Robert B. Jacobson, Aaron J. Delonay
By
Ecosystems Mission Area, Columbia Environmental Research Center

Characterization of pallid sturgeon (Scaphirhynchus albus) spawning habitat in the Lower Missouri River

Acipenseriformes (sturgeons and paddlefish) globally have declined throughout their range due to river fragmentation, habitat loss, overfishing, and degradation of water quality. In North America, pallid sturgeon (Scaphirhynchus albus) populations have experienced poor to no recruitment, or substantial levels of hybridization with the closely related shovelnose sturgeon (S. platorynchus). The Lowe
Authors
Caroline M. Elliott, Aaron J. Delonay, Kimberly Chojnacki, Robert B. Jacobson
By
Ecosystems Mission Area, Columbia Environmental Research Center

Improved genetic identification of acipenseriform embryos with application to the endangered pallid sturgeon Scaphirhynchus albus

We produced pallid sturgeon Scaphirhynchus albus embryos at five pre‐hatch developmental stages and isolated and quantified genomic DNA from four of the stages using four commercial DNA isolation kits. Genomic DNA prepared using the kit that produced the largest yields and concentrations were used for microsatellite DNA analyses of 10–20 embryos at each of the five developmental stages. We attempt
Authors
Tom Kashiwagi, Aaron J. Delonay, Patrick Braaten, Kimberly Chojnacki, Rachel M. Gocker, Edward J. Heist
By
Ecosystems Mission Area, Columbia Environmental Research Center

Evaluating flow management as a strategy to recover an endangered sturgeon species in the Upper Missouri River, USA

In the Upper Missouri River, Fort Peck and Garrison Dams limit the length of free‐flowing river available to the endangered pallid sturgeon. These barriers restrict the upstream migration of adults and downstream larval dispersal. A one‐dimensional (1D) modelling framework is currently in use to evaluate reservoir operation alternatives and to simulate drift of dispersing free embryos for differen
Authors
Susannah O. Erwin, Edward A. Bulliner, Craig J Fischenich, Robert B. Jacobson, Patrick Braaten, Aaron J. Delonay
By
Ecosystems Mission Area, Columbia Environmental Research Center

Diet and condition of age‐0 Scaphirhynchus Sturgeon: Implications for shallow‐water habitat restoration

Insufficient food during early life could limit the population growth of endangered Pallid Sturgeon Scaphirhynchus albus in the lower Missouri River. Shallow‐water habitat restoration is intended to provide nursery benefits, including food, for young sturgeon, but the effect of shallow‐water habitat on their diet is unknown. Age‐0 Pallid Sturgeon are rare, providing little opportunity for direct e
Authors
A. P. Civiello, N. J. C. Gosch, T. R. Gemeinhardt, M. L. Miller, J. L. Bonneau, Kimberly Chojnacki, Aaron J. Delonay, James M. Long
By
Cooperative Research Units

Status of knowledge of the Pallid Sturgeon (Scaphirhynchus albus Forbes and Richardson, 1905)

The Pallid Sturgeon is listed as federally endangered under the Endangered Species Act in the United States. When the species was listed in 1990 it was considered extremely rare and was poorly understood. Habitat alteration, commercial harvest, environmental contaminants, and other factors were identified as threats. Today our scientific understanding of the species and its life history requiremen
Authors
G. R. Jordan, E.J. Heist, Patrick Braaten, Aaron J. Delonay, P. Hartfield, D.P. Herzog, K.M. Kappenman, M.A.H. Web
By
Ecosystems Mission Area, Columbia Environmental Research Center

Identifying sturgeon spawning locations through back-calculations of drift

Unfavorable spawning habitat conditions have been identified as a potential limiting factor for recovery of the endangered pallid sturgeon on the Missouri River and its tributaries. After successful spawning, incubation, and hatching, sturgeon free embryos passively drift downstream and are sometimes captured by sampling crews. While spawning habitat has been identified at time of spawning through
Authors
Edward A. Bulliner, Susannah O. Erwin, Robert B. Jacobson, Kimberly A. Chojnacki, Amy E. George, Aaron J. Delonay
By
Ecosystems Mission Area, Columbia Environmental Research Center

Ecological requirements for pallid sturgeon reproduction and recruitment in the Missouri River—Annual report 2014

The Comprehensive Sturgeon Research Project is a multiyear, multiagency collaborative research framework developed to provide information to support pallid sturgeon recovery and Missouri River management decisions. The project strategy integrates field and laboratory studies of sturgeon reproductive ecology, early life history, habitat requirements, and physiology. The project scope of work is dev
Authors
Aaron J. Delonay, Kimberly A. Chojnacki, Robert B. Jacobson, Patrick J. Braaten, Kevin J. Buhl, Caroline M. Elliott, Susannah O. Erwin, Jacob D.A. Faulkner, James S. Candrl, David B. Fuller, Kenneth M. Backes, Tyler M. Haddix, Matthew L. Rugg, Christopher J. Wesolek, Brandon L. Eder, Gerald E. Mestl
By
Ecosystems Mission Area, Columbia Environmental Research Center
link

New Evidence Shows Endangered Pallid Sturgeon Spawned in Lower Missouri River

Three tiny fish larvae that were captured by U.S. Geological Survey scientists in May 2014 have just been confirmed to be pallid sturgeon. These new...
Read Article

Science and Products